Ethylene chlorohydrin, an intermediate product used in the manufacture of polysulfide elastomers, such as the "Thiokols," is also utilized in the synthesis of certain pesticides, paints, and varnishes, and as a solvent in the preparation of cellulose acetate. There are several known methods for the preparation of ethylene chlorohydrin, none of which are entirely satisfactory.
One method for the preparation of ethylene chlorohydrin from ethylene and chlorine in aqueous medium is described in French Pat. No. 1,511,682. This method presents the drawback of yielding a dilute solution, from which it is difficult and costly to extract the ethylene chlorohydrin in anhydrous (dry) form because of the formation of an azeotrope containing 58% of water and 42% of ethylene chlorohydrin and having a boiling point of 97.8.degree. C.
Another technique for the preparation of ethylene chlorohydrin, described in German Patent No. 968,902, consists of passing a gas containing ethylene oxide into some ethylene chlorohyrin saturated with hydrochloric acid. This manner of operating results in the formation of higher products (in the series): diethylene glycol chlorohydrin (CHDEG) CH.sub.2 OH--CH.sub.2 --O--CH.sub.2 --CH.sub.2 Cl and triethylene glycol chlorohydrin (CHTEG) CH.sub.2 OH--CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CH.sub.2 Cl; and therefore the yield in ethylene chlorohydrin (CHEG) does not exceed 80-90%.
Russian inventor's Certificate No. 422,241 discusses the method for the preparation of ethylene chlorohydrin by reaction, in the liquid phase, of ethylene oxide with previously purified hydrochloric acid and cites the drawbacks of this method. According to the technique described in this Russian inventor's Certificate No. 422,241, the disadvantages of this method are remedied by having ethylene oxide and moist (wet) hydrochloric acid react in the presence of an organosilane. However, this method does not permit a yield exceeding 88-92% of ethylene chlorohydrin.